1. Field of the Invention
The invention concerns a method for the application of marking on a road surface by use of a material which is viscous at the moment of application, and which from a supply chamber is led under pressure through a discharge opening, after which a number of rotating blades sweep-off the material which is thereafter thrown against the road surface in the formation of the marking, and an application apparatus for the execution of the method.
2. Description of the Prior Art
Road markings in the form of road stripes are known either as punctiform markings or as transverse beams. These forms of markings are expedient since they are not only very visible because they reflect light over a broad spectrum, but also provide good draining-off conditions for the water on the road. Moreover, driving over the markings will result in fairly strong vibrations as a warning to the driver of the vehicle.
In order to safeguard against skidding, it is known to add various friction-promoting additives to the material before it is led out and applied.
This additive can e.g. be sand, gravel, quartz grains or crushed glass.
However, the use of such additives leads to such great wear on parts of the application apparatus, especially the part around the discharge opening and the blades, that this results in a seriously limited lifetime and herewith frequent replacement of parts and repairs.
An apparatus which has been developed for use without additives is known from the description of DK 166378 B.
It appears from this publication that the individual blades sweep the discharge openings and the ledge on which the material is led out.
Naturally, this physical contact gives rise to a certain degree of wear, but this in itself is not so great that it limits the use of the apparatus.
However, if the material supplied contains additives in the form of hard materials, this will have such a harmful effect on both the discharge part and the blades that after a short period of use the apparatus is no longer functional.
The invention overcomes the disadvantages and drawbacks of the known methods, and this is achieved according to the invention by a method whereby the material is fed out in a coherent material flow, and blades carry the material flow from the free end thereof at a distance from the discharge opening.
In a simple manner, it is hereby achieved that the material can be carried by the blades completely without the material getting xe2x80x9cpinchedxe2x80x9d between the supply parts and the blades.
The additive will thus neither damage nor give rise to wear or deformations on the mechanical parts of the apparatus, and therefore the method permits a trouble-free application of the material, even when it contains additives in large amounts or with large grain sizes.
By configuring the apparatus of the invention with blades which move past the delivery opening(s) at a relatively great distance, the apparatus will be able to effect the method without any reduction in the speed of application or the quality of the marking.
By providing the apparatus with several discharge openings each with their own shutter, the flow of material can be dimensioned so that the marking on the road has a sloping or convex cross-sectional form.
By mounting the blades at mutual distances on an axle, the axial length of the blades will be limited and the amount of material swept off will therefore be correspondingly limited.
By configuring the blades with full length across the discharge openings, the markings which result will be in the form of transverse beams.